The present invention relates to a compressor comprising a plurality of pairs of a cylinder bore and a piston moving reciprocally in the cylinder bore, a valve plate provided with a plurality of outlet holes for leading pressurized gas in the cylinder bores to the outside, a plurality of strap-shaped outlet valves, each whereof is free at one longitudinal end opposing a corresponding one of the outlet holes to open and close it, and a plurality of retainers, each whereof extends in the same direction as a corresponding one of the outlet valves and is provided with a divergence restricting surface opposing the valve plate with the corresponding outlet valve extending between the surface and the valve plate to restrict the divergence of the corresponding outlet valve.
Japanese Utility Model Laid-Open Publication No. 05-073276 discloses a compressor comprising a plurality of pairs of a cylinder bore and a piston moving reciprocally in the cylinder bore, a valve plate provided with a plurality of outlet holes for leading pressurized gas in the cylinder bores to the outside, a plurality of strap-shaped outlet valves, each whereof is free at one longitudinal end opposing a corresponding one of the outlet holes to open and close it, and a plurality of retainers, each whereof extends in the same direction as a corresponding one of the outlet valves and is provided with a divergence restricting surface opposing the valve plate with the corresponding outlet valve extending between the surface and the valve plate to restrict the divergence of the corresponding outlet valve.
In the aforementioned compressor, the retainer restricts the distance of lift of the outlet valve when the outlet valve opens i.e., divergence of the outlet valve to prevent the divergence from becoming too large, thereby controlling noise generating when the outlet valve touches the valve seat.
The compressor disclosed in Japanese Utility Model Laid-Open Publication No. 05-073276 has a problem in that all the outlet valves are forced to have the same divergence to behave in the same manner and vibrate with the same frequency, thereby causing a marked vibration of the compressor and pulsation of the gas with the aforementioned specific frequency of the vibration of the outlet valves.